Federal and state governments have imposed increasingly strict regulations over the years governing the levels of hydrocarbon (HC), carbon monoxide (CO) and nitrogen oxide (NOx) pollutants that a motor vehicle may emit to the atmosphere.
In diesel engine systems, a diesel particulate filter (DPF) is provided to trap the particulate matter in the exhaust passage of the diesel engine. Conventionally, a dosing valve is mounted into the exhaust manifold of a diesel system to inject diesel fuel into the exhaust to reduce the particulate matter and thus reduce NOx emissions. Since the temperature of the exhaust manifold can reach 600 C, water cooling is required to ensure that the valve survives.
Thus, there is a need to eliminate water cooling of an exhaust dosing valve and to reduce the number of components of a dosing valve system.